The present invention relates to a universal stand for rolling having a horizontal and vertical rolls arranged on a common plane that extends transversely to the direction of rolling, wherein the vertical rolls as well as their respective mounts and adjusting devices are arranged in a center frame by means of which the upper and lower horizontal roll mounts are adjustable and releasable through tie rods there being a general mounting platform. Also, it is assumed that the rolls are not mounted in the usual roll housing.
The invention relates particularly to a universal roll of the variety as disclosed in German printed patent application No. 25 15 651. According to this patent the horizontal rolls are mounted in eccentric sleeves for adjusting purposes. In the case of an exchange and replacement of the rolls the biased tie rods have to be load relieved and the upper as well as lower mounts for and including the horizontal rolls themselves and also the eccentric adjusting device, all have to be removed from the tie rods by a crane or the like.
Another universal rolling mill is known through earlier German printed patent application No. 20 02 745. Herein rolls are adjusted through eccentric devices with extension pieces for application of tension and there is also a central frame which bears on a bottom plate. The adjustment is also here obtained through an eccentrical device which permits a compact frame construction and is not much subject to physical expansion, but again the short adjusting paths are nothing but a tradeoff for a disadvantageous time consuming procedure upon for exchanging and replacing rolls.
Another type of universal rolling mill with tie rod is known wherein the tie rods are rotatably mounted in the center frame for the vertical rolls. This way the upper and lower parts including horizontal roll mounts, rendered movable in vertical direction. This construction is also disadvantaged by the fact that an exchange of the rolls is rather complicated and time consuming because a frame cap has to be removed first before a roll exchange and replacement can take place which is carried out generally in upper direction. This kind of an arrangement is shown in German printed patent application No. 25 06 449.
The German Pat. No. 21 44 511 discloses a universal roll of similar kind which however is disadvantaged by a reduced stiffness of the frame owing to the tension of and in the very long unbiased tie rods.
German Pat. No. 11 29 441 discloses a universal stand which is comprised of an upper part, a center part and a lower part which are interconnected by tension rods so as to establish a unit. This kind of frame construction is simpler as compared with other known universal roll stand and is stiffer on account of smal distances between the columns in the stand. However, this kind of construction is disadvantaged by the exchange and removal of rolls since the exchange is possible only through a rather complex and time consuming removal of upper and central parts. This kind of construction, moreover, is believed to offer even more time consuming roll exchange procedures than the roll exchange in the other cases discussed earlier.
For all these situations it has to be observed that in modern mills the rolling program is changed relatively frequently and whenever the rolls have to be exchanged or replaced, then all these instances offer cumulatively an operational down time that can become quite excessive.